1. Field of the Invention
The invention relates to an enhanced hardware arrangement for mounting a plurality of circuit boards together, and in particular, to an enhanced arrangement for mounting an array connector, a processor card and a backplane together.
2. Background Information
Backplanes are wiring boards, which are a type of circuit board used in computers, and are typically connected to various other circuit boards, such as a processor card and a so-called memory riser card. Further, it is typical to attach a clock card, which is a further type of circuit board, to the backplane. This assembly of the backplane and various circuit boards may then be positioned within an open cage, which is a frame fixed within, for example, a computer housing. The cage serves to position the circuit boards within the computer housing.
During operation, the various electrical components located on the circuit boards, for example the processor modules attached to the processor card, tend to consume a substantial amount of electrical power, and therefore tend to generate a substantial amount of heat. Because excess temperature can impair a computer system's reliability and functionality, the processor cards are provided with heat sinks in a region of their respective processor modules, to help dissipate the generated heat. On some processor cards, the heat sinks are provided in such a high density that nearly the entire surface of the card is covered by heat sinks. For example, the processor card may be provided with two or more processor modules soldered to a surface of the card, with each module containing, for example, two processor chips. Each of these chips would typically be connected to its own respective heat sink, which is conventionally positioned over its corresponding chip. Further, the processor card may also be provided with one or more memory modules, each of which likewise will typically be provided with a respective heat sink.
Typically, circuit boards are electrically connected to the backplane in a permanent relationship by soldering the circuit boards directly to the backplane. This type of connection disadvantageously prevents the circuit board from being easily removed from the backplane for repair or replacement purposes. Alternatively, the circuit boards can be connected to the backplane using a pin-and-socket connector. However, this type of connection disadvantageously requires a substantial amount of space in order to accommodate the necessary connectors, and results in a relatively high impedance between the circuit boards and the backplane. As is known to those skilled in the art, a high impedance is undesirable, since this may attenuate the signal strength between the backplane in the associated circuit board.
It is also known to use an array connector in order to electrically connect a circuit board to a backplane. Such connectors are typically composed of a relatively small, flat panel having a relatively large number of conductive pads formed thereon. For example, an array connector may have a rectangular profile, and be about three centimeters in height by six centimeters in length. An array of conductors, for example silver pins, are provided. Each conductor extends entirely through the panel to project slightly beyond both of the panel's opposing surfaces. The conductors are arranged in an array, for example, of twenty-five rows, by forty-one columns (i.e., 1025 conductors).
The array connector is positioned between the backplane and the associated circuit board, with the conductors engaging with, and providing an electrical connection between, respective wirings located on the backplane and the circuit board. In order to ensure an electrical connection between the circuit board and the backplane, it is necessary that each conductor of the array connector be pressed against the associated respective wirings. Thus, a relatively large force, for example, 180 pounds of force, is typically applied in such a manner that the array connector is held under pressure between the circuit board and the backplane. Typically, this force is generated through the use of a relatively large, expensive, complicated arrangement of springs and screws which are positioned at each of the four corners on the array connector. However, since space is often limited, this type of arrangement may not be suitable for many computer applications. For example, since processor cards are typically provided with a plurality of heat sinks, as described above, the location of the heat sinks may interfere with the above-described arrangement of springs and screws, thus prohibiting the use of an array connector with certain processor cards. Thus, there is a need for a connector that it is suitable for securely holding an array connector between two circuit boards, such as a backplane and a processor card, using a minimum amount of space.
Additionally, the known arrangement for securing an array connector to circuit boards is difficult to use, due to its complexity. Further, access to the springs and screws of the known arrangement may be limited. Therefore, there is a need for an arrangement for securing an array connector between two circuit boards, such as a backplane and a processor card, that is easy to use.
Furthermore, the conductors of the array connector will typically compress due to the applied force over a period of time. This will result in a gradual reduction in the applied force, which may ultimately result in the electrical connection between the backplane and the circuit board failing. Thus, there is a need for a way to apply the necessary force to an array connector which will not diminish over a period of time.